Chapter 4 Measures Fundamentals of Measurement • Conceptual Variables – Words (self-esteem, parenting style, brain size, depression, cognitive development) • Measured Variables – Numbers that represent the conceptual variables Operational Definition • Operational Definition – refers to a precise statement of how a conceptual variable is turned into a measured variable Measurement Scales • Ratio (multiply & divide) • Interval (add & subtract) • Ordinal (ordered) • Nominal Self-Report Measures • Free-Format Self-Report Measures – asking people to freely list their thoughts or feelings as these come to mind Self-Report Measures Free-Format Self-Report Measures • Projective Measures – a measure of personality in which an unstructured image, such as an inkblot, is shown to participants, who are asked to freely list what comes to mind • Thematic Apperception Test (TAT) • Rorschach Inkblots Self-Report Measures Free-Format Self-Report Measures • Associative Lists – people are given lists of groups and asked to list whatever thoughts come to mind Self-Report Measures Free-Format Self-Report Measures • Think-Aloud Protocols – in this procedure, participants are asked to verbalize into a recorder the thoughts that they are having as they complete a task Self-Report Measures • Fixed-Format Self-Report Measures – on these measures, the participants are presented with a set of questions, and the responses that can be given are more structured than free-format measures • Example: What is your gender: male___, female___, other___? Self-Report Measures Fixed-Format Self-Report Measures • Likert Scales – the most popular type of fixedformat scale • Try to control for acquiescent responding (yeahsaying bias) – people who tend to agree with everything • Reverse Coding Limitations in Self-Report Measures • People may not be able to accurately selfreport on the causes of their behavior • People may not want to accurately self-report on the causes of their behavior • Reactivity – changes in responding that occur when individuals know the are being measured • Social Desirability & Self-Promotion Behavioral Measures • An alternative to self-reports is to measure an actual behavior. Advantages of Behavioral Measures • Behavioral measures do not involve direct questioning of people, therefore, they are often less reactive Advantages of Behavioral Measures • Participants are particularly less reactive when: 1. They are not aware measurement is occurring 2. They are not aware what the measure is designed to assess 3. They cannot change their responses even if they desire Behavioral Measures • Frequency – example: frequency of stuttering as a measure of anxiety in interpersonal relations • Duration – example: the number of minutes working at a task as a measure of task interest Behavioral Measures • Intensity – example: how hard a person claps his or her hands as a measure of effort • Latency – example: the number of days before a person begins to work on a project as a measure of procrastination • Speed – example: how long it takes a mouse to complete a maze as a measure of learning Nonreactive Measures • Used to assess attitudes that are unlikely to be directly expressed on self-report measures Nonreactive Measures • Example: When participants interviewed people of different races, there were differences in how close they sat to the interviewees, made more speech errors, and terminated the interviews sooner Psychophysiological Measures • • • • • Electroencephalogram (EEG) Computer Assisted Tomography (CAT) Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET) Functional Magnetic Resonance Imaging (fMRI) Electroencephalogram (EEG) Computer Assisted Tomography (CAT) Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET) Functional Magnetic Resonance Imaging (fMRI) Electromyograph (EMG) Heart Rate Blood Pressure Respiration Speed Skin Temperature Skin Conductance Cortisol Levels Multiple Measures (Mixed Measures) • The use of Self-Report Measures combined with Behavioral Measures (Psychophysiological Measures) provides superior validity